Fifteen years ago, from a hole in the ground in rural Washington, a tiny flying machine emerged and Charles Hoy found it. From all appearances, this small vehicle wasn't built with any existing human technology and Hoy made a fortune selling that technology to the first eager customer. Now with his fortunes dwindling, Hoy has hired a team of adventurers to enter this vast, underground realm in hopes of bringing back even greater discoveries. But while the team expects the unexpected and is prepared for danger nothing has prepared them for The World Below!